Paucituberculata is an order of South American marsupials. Although currently represented only by the seven living species of shrew opossums, this order was formerly much more diverse, with more than 60 extinct species named from the fossil record, particularly from the late Oligocene to early Miocene epochs. The earliest paucituberculatans date to the late Paleocene. The group went through a pronounced decline in the middle Miocene epoch, which resulted in the extinction of all families of this order except for the living shrew opossums (Caenolestidae). Extinct families of Paucituberculatans include Pichipilidae, Palaeothentidae, and Abderitidae.
The family Caenolestidae contains the seven surviving species of shrew opossum: small, shrew-like marsupials that are confined to the Andes mountains of South America. The order is thought to have diverged from the ancestral marsupial line very early. They were once included in the superorder but it is now known that Ameridelphia is paraphyletic, having given rise to Australidelphia, and thus could be considered an evolutionary grade. Genetic studies indicate that they are the second most basal order of marsupials, after the didelphimorphs. As recently as 20 million years ago, at least seven genera were in South America. Today, just three genera remain. They live in inaccessible forest and grassland regions of the High Andes.
The long-nosed caenolestid, also known as the Chilean shrew opossum or long-nosed shrew opossum, is a shrew opossum that occurs in temperate forests of Argentina and southern Chile. It was first described by American zoologist Wilfred Hudson Osgood in 1924. The long-nosed caenolestid resembles Caenolestes species in morphology. It is characterized by a long, pointed snout, small eyes and ears, and one claw on a digit of each of the thin limbs. Little is known of its behavior; it appears to be terrestrial, nocturnal and omnivorous. It prefers cool, moist areas, and has a small distribution. It is classified as near threatened by the IUCN.
The dusky caenolestid, also known as Tate's shrew opossum, is a shrew opossum from South America. The dusky caenolestid is characterized by a dark brown coat with a lighter underbelly, soft and thick fur, and a loosely haired tail. A nocturnal animal, the dusky caenolestid lives on trees and feeds on insects and small invertebrates and vertebrates. It occurs in alpine and páramo forests in northern and western Colombia, Ecuador, and western Venezuela. The IUCN classifies this shrew opossum as least concern.
The brown-eared woolly opossum, also known as the western woolly opossum, is an opossum from South America. It was first described by German naturalist Ignaz von Olfers in 1818. The opossum is characterized by a brown to reddish brown coat and similarly colored limbs, yellow to orange underbelly, hairless, brown ears with a hint of pink, and a tail furred on the back for up to half of its length. The brown-eared woolly opossum is nocturnal, solitary and omnivorous. The IUCN lists it as least concern.
Anderson's four-eyed opossum is an opossum species from South America. It is found in Brazil, Colombia, Ecuador, Peru and Venezuela. Its dorsal fur is dark, with a black stripe, about 3–4 cm wide, going vertically down the midline of its back. Its dorsal fur is short, about 10 mm long. Its ventral fur is dark gray, but still distinctly lighter than the sides and dorsum. Its tail is furred for the first (approximately) 18% of its length, going from the base to the tip. Its species name "andersoni" was chosen to honor American scientific collector Malcolm Playfair Anderson.
The common shrew opossums are members of the family Caenolestidae. They are found in Colombia, Ecuador, Peru, and Venezuela. The most recently discovered species is C. sangay.
The nine species in the genus Philander, commonly known as gray and black four-eyed opossums, are members of the order Didelphimorphia. Mature females have a well-developed marsupium. The tail appears to be hairless except for the proximal 5 or 6 cm, which has a few long hairs. The tail is slightly longer than the head-and-body length, and it is black for the proximal one half to two thirds of its length. The genus is closely related to Didelphis but the species of Philander are smaller than those of Didelphis. The genus formerly included Metachirus nudicaudatus, but this species lacks a pouch and so is now considered a separate genus. The common name comes from the white spots above the eyes, which can appear from a distance to be another set of eyes.
The dwarf fat-tailed mouse opossum, also known as the velvety fat-tailed opossum is an opossum species from South America. It is endemic to Brazil, where it is found in cerrado and caatinga habitats. Its head-and-body length is about 141-212 mm, and its tail length is about 73-85 mm. Its diet is 44% arthropods; 75% of its diet consists of animals and animal products. Its ventral fur is entirely gray-based. Its hind foot is less than 14 mm, which is short for the genus.
Derby's woolly opossum, or the Central American woolly opossum, is an opossum found in deciduous and moist evergreen forests of Central America, from southern Mexico to western Ecuador and Colombia. It was first described by English naturalist George Robert Waterhouse, and named in honor of Edward Smith-Stanley, 13th Earl of Derby. Derby's woolly opossum is the largest in its genus, with a total length of 60 to 70 centimetres and weight between 200 and 400 grams. The coat is brown and the underside white-buff to golden-brown. The opossum is nocturnal, arboreal (tree-living) and solitary. Diet consists of fruits, nectar, small invertebrates and vertebrates. The time when breeding takes place varies geographically. The litter size ranges from one to six. The IUCN classifies this opossum as least concern.
Thylamys is a genus of opossums in the family Didelphidae. The premaxillae are rounded rather than pointed. The females lack a pouch. The females' nipples are arranged in two symmetrical rows on the abdomen. All species but T. macrurus store fat in their tails., although this is not necessarily true for all species in the genus. Fossils belonging to the genus date back to the Miocene, with the oldest specimens being found in the Cerro Azul Formation of Argentina and the Honda Group of Colombia. Genetic studies indicate that the genus may have originated around 14 million years ago.
The gray-bellied caenolestid, or grey-bellied shrew opossum, is a shrew opossum found in humid, temperate forests and moist grasslands of western Ecuador and northwestern Peru. It was first described by American zoologist Harold Elmer Anthony in 1921. Little is known about the behavior of the gray-bellied caenolestid. It appears to be terrestrial (land-living) and crepuscular or nocturnal. Diet consists of invertebrate larvae, small vertebrates and plant material. The IUCN classifies the gray-bellied caenolestid as near threatened.
The Incan caenolestid, also known as the Incan shrew opossum or Peruvian caenolestid, is a caenolestid found in the southern Peruvian Andes. It was first described by English zoologist Oldfield Thomas in 1917. The head-and-body length ranges from 9 to 11.5 centimetres, and the weight is between 25 and 32 grams. It is brown on the back, and lighter on the underside. Little is known about the behaviour of the Incan caenolestid; it appears to be terrestrial and nocturnal. It feeds on small invertebrates and insects. This caenolestid inhabits elfin and secondary forests. The IUCN classifies it as least concern.
The Andean caenolestid, also known as the Andean shrew opossum or Condor caenolestid, is a shrew opossum known only from Cordillera del Cóndor (Ecuador), its type locality. It was first described by zoologists Bruce D. Patterson and Luis Albuja in 1996. It is the largest caenolestid. The IUCN classifies it as vulnerable. As of 2015, the population is estimated at less than 1,000.
The Cinderella fat-tailed mouse opossum is a species of opossum in the family Didelphidae. It is found in northern Argentina and southern Bolivia, in the eastern foothills of the Andes. Its dorsal fur is gray brown to dark brown. Its ventral fur is gray-based, except for the white to yellowish chest hairs. It has been distinguished from T. sponsorius by the well-developed postorbital ridges of the latter, but mitochondrial DNA sequence analysis does not support separate species status for sponsorius.
The Argentine fat-tailed mouse opossum was formerly considered a species of opossum in the family Didelphidae. It is found in the eastern foothills of the Andes in northern Argentina and southern Bolivia. Typically reach around 10-13 cm in body length, with a bushy tail adding another 12-15 cm. Its dorsal fur is gray brown to dark brown. Its ventral fur is gray-based except for the white to yellowish chest hairs. It has been distinguished from T. cinderella by its postorbital ridges. T. cinderella has well-developed postorbital ridges in both juveniles and adults that extend laterally behind the eye sockets. Only adults of T. sponsorius have fully developed postorbital ridges, and these do not extend laterally behind the eye sockets. While the American Society of Mammalogists maintains this as a distinct species, mitochondrial DNA sequence analysis does not support the population being distinct from T. cinderella.
Christian Miguel Pinto Baez, often stated as C. Miguel Pinto or Miguel Pinto, is an Ecuadorian zoologist noted for his research work on rodents, small carnivora, and bats from the Neotropics and their parasites. He worked as a research scientist at the Department of Mammalogy of the American Museum of Natural History until he was banned from the Smithsonian because of sexual harassment findings, and as of November 2016, held a research position at the National Polytechnic School in Quito, Ecuador.
The eastern caenolestid is a shrew opossum found on the eastern slopes of the Andes in southern Ecuador.
